The invention concerns a method for providing electric energy for an engine control unit before start of an internal combustion engine of a hand-held power tool which engine is to be started by means of a rope starter, wherein for the electric energy of the engine control unit a voltage source is provided.
The invention also concerns a device for providing an engine control unit with electric energy before start of an internal combustion engine that is to be started by means of a rope starter, the device comprising a voltage source for the electric energy of the engine control unit.
Hand-guided power tools like motor chain saws, trimmers, cut-off machines, pole pruners, and suction/blower devices are often equipped with an internal combustion engine that is started generally by means of a rope starter. A generator arranged in the power tool is driven by the crankshaft so that in operation of the internal combustion engine a sufficient voltage supply is available for the ignition circuit and engine control unit. In the starting phase, i.e., from performing the first rope stroke or pull to reaching a predetermined engine speed, the voltage delivered by the generator is not enough to ensure an immediate function of the engine control unit or the microprocessor-controlled ignition. For eliminating this disadvantage, it has already been suggested to employ a battery that provides the power required during starting for operating the engine control unit or the electronic ignition during the starting phase of the internal combustion engine. However, such a battery must be exchanged based on the load frequency or after a certain time, i.e., the battery must be serviced and regular charging is necessary to ensure a good starting readiness of the internal combustion engine.
It is the object of the present invention to provide a method for supplying electric energy for an engine control unit of the aforementioned kind with which in an easy manner the electric energy can be generated and stored. Moreover, the object resides in providing a device for performing the method for generating and storing the electric energy.